Method and means for beneficiating ores



, Patented Oct. 23, 1952 3,059,774 MEANS FOR BENEFIQIATING GEES MartinWilson, Anaheim, Calif., assignor to United States Borax & (IhemicalCorporation, Los Angeles, Calif., a corporation of Nevada No Drawing.Filed July 31, 1961, Ser. No. 127,855 1 (Zlaim. 81. 209166) The presentinvention is a continuation-in-part application of my applicationbearing Serial No. 12,249, dated March 2, 1960, now abandoned.

This invention relates as indictaed to the beneficiation of ores and hasmore particular reference to reagents used in the froth flotation ofvarious types of ores.

It has long been the desire of ore refiners to economically separatedesirable minerals from ores by froth flotation, and to obtain a finalproduct having a particle size on the order of from 6 to 8 mesh and of apurity which meets the specifications of the industry. Effective frothflotation techniques and reagents for recovering minus 16 mesh particlesof the desired minerals from their respective ores have been known.However, these prior art techniques and reagents have been ineffectivein the recovery of plus 14 mesh particles and the ore refiners have hadto resort to the use of additional operations and equipment in order toobtain particles 14 mesh or larger. This has resulted therefore inprocesses which are costly and inetficient.

It is, therefore, the principal object of this invention to provide aneconomical method and means for the froth flotation of ores, which willresult in a final product having a particle size on the order of atleast 8 mesh and of a desired purity.

Another object of this invention is to provide new, economical andefficient froth flotation reagents which will eliminate the use ofadditional costly equipment.

Other objects will appear as the description proceeds.

To the accompaniment of the foregoing and related ends, the inventionthen comprises the features hereinafter fully described and particularlypointed out in the claim, the following description setting forth indetail certain illustrative embodiments of the invention, these beingindicative, however, of but a few of the many ways in which theprinciple of the invention may be employed.

Broadly stated, the present invention comprises the method of obtainingdesired mineral values from ores by froth flotation, which comprisespulping said ore, conditioning the resultant ore pulp with a flotationreagent comprising an admixture of a long chain aliphatic amine and amaterial selected from the group consisting of alkylnaphthalenes, thealkyl portion of which contains from 1 to 8 carbon atoms,chloroalkylnaphthalenes, the alkyl portion of which contains from 1 to 8carbon atoms, hydrogenated alkylnaphthalenes, the alkyl portion of whichcontains from 1 to 8 carbon atoms, hydrogenated chloroalkylnaphthalenes,the alkyl portion of which contains from 1 to 8 carbon atoms,alkylmercaptans, the alkyl METHOD s portion of which contains from 4 to18 carbon atoms,

aryl substituted alkylmercaptans, the alkyl portion of which containsfrom 2 to 8 carbon atoms, dialkyl sulfides, the alkyl portion of whichcontains from 4 to 18 carbon atoms, aryl substituted dialkyl sulfides,the alkyl portion of which contains from 2 to 8 carbon atoms, dialkyldisulfides, the alkyl portion of which contains from 4 to 18 carbonatoms, and dialkyl polysulfides, the alkyl portion of which containsfrom 4 to 18 carbon atoms, subjecting said conditioned ore pulp to afroth flotation cell and recovering said mineral values from said cell.

From the foregoing broadly stated paragraph it will be seen that thepresent invention uses a combination of flotation reagents to conditionthe pulped ore so as to obtain the desired mineral values. The presentadmixture comprises as one component, long chain aliphatic aminecollectors which are well known to those skilled in the flotation art.These collector reagents, which selectively coat the desired mineralvalues in the ore pulp, do not impart sufiicient hydrophobic characteristics to the desired mineral values, and consequently, are not able tofloat particles larger than about 16 mesh. However, by the addition ofthe above substituted naphthalene and organosulfide auxiliary reagentsit is now possible, for the first time, to float by froth flotationparticles as large as 6 or 8 mesh.

It is my theory that the amine collector reagents attract the auxiliaryreagents which in turn impart a much greater hydrophobic characteristicto the desired mineral values and bring about the flotation of particlesas large as 6 or 8 mesh. However, regardless of Whether my theory iscorrect or not, the fact remains that by combining any of the well-knownamine collectors with the above-defined substituted naphthalene andorganosulfide com pounds, it is now possible to efliciently andeconomically float particles, by froth flotation, as large as 6 or 8mesh.

As stated above, the amine collector reagents used in the presentinvention are the same as those used by ore refiners in prior flotationprocesses. These collector reagents are long chain aliphatic aminesconsisting of from 7 to 18 or more carbon atoms and are most commonlyprepared from beef tallow. They are usually prepared as the salts of theamines, the most commonly used salt being the acetate, and they arepurchased commercially as mixed aliphatic amine acetates.

The auxiliary reagents applicable to the present invention are thealkylnaphthalenes, the chloroalkylnaphthalenes, the hydrogenatedalkylnaphthalenes, the hydrogenated chloroalkylnaphthalenes, thealkylmercaptans, the dialkyl sulfides, the dialkyl disulfides, thedialkyl polysulfides, the aryl substituted alkylmercaptans and the arylsubstituted dialkyl sulfides. The following list is illustrative of theauxiliary reagents which are useful in the present invention:

Methyl naphthalene Ethyl naphthalene Propyl naphthalene Amyl naphthaleneOctyl naphthalene Chloromethyl methylnaphthalene Methyltetralin IEthyltetralin Methyldecalin fi-Chloroethyltetralin Ethyldecalin.t-Butylmercaptan t-Hexylmercaptan t-Octylmercaptan n-Dodecylmercaptant-Tetradecylmercaptau t-Hexadecylmercaptan PhenylethylmercaptanPhenylpropylmercaptan Di-n-butyl sulfide Di-t-heptyl sulfideDiphenylethyl sulfide Di-t-amyl disulfide Di-t-heptyl disulfideDi-t-tetradecyl disulfide Di-t-butyl polysulfide Di-t-octyl polysulfideDi-t-dodecyl polysulfide It is to be clearly understood that theforegoing list is only a partial enumeration of the auxiliary reagentsapplicable to the presentinvention and is not intended to limit theinvention.

The auxiliary reagents may be used individually, or in any combination,with the amine collector reagents; however, the fact remains that atleast one auxiliary reagent must be used with an amine collector reagentin order to float material having a particle size greater than about 16mesh.

Froth flotation is used in two ways for the beneficiation of ores. Inone instance the desired mineral value is recovered from the froth, suchas in the flotation of:

(a) Potassium values from potassium bearing ores;

(b) Spodumene from silica and mica feldspar; (c) Mica and silica fromcement rock;

while in the other instance the impurities are floated and discarded andthe desired mineral values are recovered from the flotation cell, suchas in the flotation of:

(a) Silica from ilmenite;

(b) Silica from lepidolite;

(c) Calcite and silica from fluorspar; (d) Silica from phosphate bearingores; (e) Silica from iron bearing ores.

Sylvinite ore was ground to a minus 8 mesh size and was slurried in asaturated brine composed of the soluble constituents of the ore. Theslurry was then deslimed through a 100 mesh screen to remove the finesand insoluble matter. The ore pulp was then conditioned with anadmixture of auxiliary reagent and amine collector reagent, and theconditioned ore pulp was added to a Fag flotation cell along with someclear saturated brine. The slurry was then aerated from the bottom ofthe cell and as froth formed at the surface it was removed carrying withit substantially all of the potash.

The following table shows results of tests performed following the aboveprocedure. The rate of addition of reagents is measured in pounds ofreagent per ton of crushed ore and the percent potassium chloriderecovered is based on the percent potassium chloride in the ore pulpafter desliming.

Table I Auxil- Col- Percent Auxilimy Reagent iary leetor KCl Re-Rengent, Reagent, covered lb./ton lb./tou

Substituted Naphthalenes:

Methyl naplithalene 0. 38 0. 38 94. 65 Ethyl naphthalene 0. 35 0. 38 Q5.21 Arnyl naphthalene. 0.38 0. 38 95. 96 Oet-yl naphthalene 0. 35 0.3895. 14 Chlororrethyl methylnap 0.35 0.38 94. 87 Methyldecalin 0. 35 0.3895. 22 fl-Chloroethyltetralin 0. 35 0. 38 95. 14 Organosulfides:

t-Octylmercaptau 0. 35 0. 38 94. 96 n-Dodeeylmereaptan 0. 35 0. 38 95.47 t-Dodeeylmercaptan O. 38 0.38 95. 29 t-Tetradccylmercaptau 0. 35 0.3895. 50 t-Hexndecylmereaptan 0. 35 9. 38 94. 98 Phenylethylmercaptau 0.35 0. 38 94. 89 Diphenylethylmercaptau. O. 35 0. 38 95.02Di-t'amylsulfide 0. 35 0. 38 95. 36 Dl-l'll)lllylSlllfidG. 0. 38 0. 3895. 2S D1-tdo(leeyldisulfide. 0.35 0.38 96. Di-t-octyldisulfide 0.350.38 95.81 Di-bdodeeylpolysulfidm- 0. 0.38 95. 13 Di-t-amylpolysulfide0.35 0.38 95. 04 l l l t 0 18 ror eey mercap an Amyl naphtlialene 0. 17l 3S 62 t-Hexadccylmercaptnu 0.18 0 38 95 38 Ethyl n aphthalene. 0.17None 0 0.75 82. 46

Sylvinite ore was ground to a minus 8 mesh size and was slurried withbrine comprised of the soluble constituents of the ore. The slurry Wasthen deslimed through a 100 mesh screen to remove the fines andinsoluble matter, and the deslimed ore was wet screened and divided intotwo fractions, one fraction containing the plus 16 mesh particles, theother fraction containing the minus 16 mesh particles. The plus 16 meshfraction was conditioned with an admixture of auxiliary reagent and theminus 16 mesh fraction was conditioned with only amine collectorreagent. After conditioning, the two fractions were added to a Fagflotation cell along with some clear saturated brine. The slurry wasthen aerated from the bottom of the cell and as the froth formed at thesurface it was removed carrying with it substantially all of the potash.

The following table shows results of tests performed as per the aboveprocedure. The rate of addition of reagents and the percent potassiumchloride recovered are measured on the same basis as in Example I.

Table II +16 Mesh Fraction 16 Mesh Fraction Auxiliary Reagent AuxiliaryCollector Collector Percent Reagent, Reagent, Reagent, K01 Relb./tonlb./ton lb./ton covered Substituted Naphthalenes:

Methyl naphthalene"--- 0.18 0.20 0.12 94. 97 Ethyl naphthulcue 0. 1S 0.20 0.12 95.57 Amyl naphthalene 0. 18 0. 20 0. 12 95.92 Octylnaphtlialene 0.15 0.20 0.12 95. 02 Chloroinethyl methylnaphtlialene 0.150.20 0.12 95. 44 Methyldcenlim 0.15 0. 20 0.12 95. 40 B0hloroethyltetrahn..-.- 0. 15 0.20 0. 12 94. 89 Organosultides:

t-Octylmercaptan 0.15 0.20 0.12 94. 91 n-Dodecylniereaptau. 9.15 0. 200.12 95. 67 t-Dodeeylmereaptan. 0.18 0.17 0.15 95. 49t-Tetradecylrnereaptau. 0. 18 0. 20 0. 12 95. 16 t'Hexadeeylmereaptan-..0. 15 O. 20 0.12 95. 96 Phenylethylmereaptan- 0. 18 0.20 0. 12 95. 34Dipheuylethylniereaptan. 0. 18 0. 20 0. 12 95. 18 Di-t-aulylsulfide 0.150. 20 0.12 95. 53 Di-n-butylsultide 0. 15 0. 20 0. 12 95. G1Di-tdodeeyldisulfide 0. 15 0. 20 0.12 95.59 Di-tpctyldisullide 0.15 0.20 0. 12 95. 44 Di-t-nmylp0lysulfide 0.15 0. 20 0. 12 95. 57Di-t-dodecylpolysulfide. 0. 15 0. 20 0. 12 9G. 09 d l t 0 0 ecy mercapan.-- Afilyl ltlaplqhmcnmn g 0.20 9.12 95.92 texa eey inereaptan Ethylnaphthalene-.- 0 l i 20 96-02 None 0 0.38 0.12 69.14

The concentrates recovered, as per the examples given, ranged in gradefrom about 95.2% to about 97.7% potassium chloride, which exceeds theminimum standard of purity, 95%, as set by the potash industry.

Although there are numerous variations which can be used in performing afroth flotation process, such as conditioning the ore pulp first withthe amine collector reagent and then with the defined auxiliaryreagents, in the preferred embodiment of the invention, I use the methodas described above in Example II. I have found this method to be themost economically desirable process, as it requires a minimum ofreagents with a minimum of equipment and handling.

It is important to note that the tables from the preceding examplesindicate that the addition of auxiliary reagent and amine collectorreagent provides an efficient flotation process where amine collectorreagent alone does not. Although the examples shown are only for thebeneficiation of sylvinite ore, the combination of auxiliary reagent andamine collector reagent works equally well in any of the prior art frothflotation processes which employed only amine collector reagent, and forthe first time, provides the efficient recovery of particles as large as6 or 8 mesh.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures in the following claim or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as myinvention:

The method of obtaining sylvite from sylvinite ore by froth flotation,which comprises pulping said sylvinite ore to a particle size of atleast about 8 mesh, conditioning the resultant ore pulp with a flotationreagent comprising an admixture of a long chain aliphatic amine and amaterial selected from the group consisting of alkylnaphthalenes, thealkyl portion of which contains from 1 to 8 carbon atoms,chloroalkylnaphthalenes, the alkyl portion of which contains from 1 to 8carbon atoms, hydrogenated alkylnaphthalenes, the alkyl portion of whichcontains from 1 to 8 carbon atoms, hydrogenated chloroalkylnaphthalenes,the alkyl portion of which contains from 1 to 8 carbon atoms,alkylmercaptans, the alkyl portion of which contains from 4 to 18 carbonatoms, aryl substituted alkylrnercaptans, the alkyl port-ion of whichcontains from 2 to 8 carbon atoms, dialkyl sulfides, the alkyl portionof which contains from 4 to 18 carbon atoms, aryl substituted dialkylsulfides, the alkyl portion of which contains from 2 to 8 carbon atoms,dialkyl disulfides, the alkyl portion of which contains from 4 to 18carbon atoms, and dialkyl polysulfides, the alkyl portion of whichcontains from 4 to 18 carbon atoms, subjecting said conditionedsylvinite ore pulp to a froth flotation cell and recoveringsubstantially all of the sylvite from the resultant froth.

References Cited in the file of this patent UNITED STATES PATENTS1,904,461 Hess Apr. 18, 1933 1,904,462 Hess Apr. 18, 1933 2,381,662Gaudin Aug. 7, 1945 2,420,476 Greene May 13, 1947 3,016,143 Trachta Jan.9, 1962 FOREIGN PATENTS 1,011,166 France Apr. 2, 1952

